Way too many differing opinions here? I'll just ignore all I've read because that's all it is until I see otherwise.

Again, talking a SA only 1911 - don't take my word or anyone else's word here.
There are books and opinions by experts such as Col. Jeff Cooper, Hilton Yam & Larry Vickers on this subject. Read what they have to say.

But why? Is there really a greater chance of an AD over cocked n locked.

Yes there is a greater chance of a NEGLIGENT DISCHARGE (ND) in condition 2 as one must pull the trigger and lower the hammer to put it into that condition in the first place AND one must manually cock the hammer to "get into the fight". That is two times the possibility right there.

A "properly" set up 1911 or A1 has an inertia firing pin that will not go bang no matter how hard you hit the hammer. It is just too short to do so. Mr. Murphy has a way of getting involved in situations like this.

A classic Colt SAA is different. The firing pin is actually resting ON the primer when the hammer is at rest. They can go off from a blow to the hammer.

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Friend of mine was carrying a 3" barrelled 1911 in condition 2 for concealed carry in an under the shirt shoulder holster. Receiving a hug from his mother or mother in law... don't remember which... the shirt apparently wrapped around the hammer pulling it to a nearly cocked position and then when releasing their hug the shirt unwound releasing the hammer... hammer hit with enough force (so he said) to discharge the round putting a good size hole through the dining room wall... close call if you ask me. That is how he recounts what happened anyway...

I carry what some call half cocked. With my Sigs and 1911s it's not really half. One click back is just off the firing pin and won't allow an accidental discharged if dropped. There is no guarantee, however I prefer it. I run drills cocking the hammer while at the last point before final aim on 1911s. Be very careful releasing the hammer if you choose to carry this way. Most Sigs have a de-cocking lever and the first click for safety, then DA/SA. It is my recommended safe and reliable carry weapon. Just my opinion.

Many, MANY firearm instructor, and authorities will recommend that a single action semi auto be carried "cocked and locked". I will defer to their experience. When someone with the credentials of Col. Jeff Cooper can articulate why another method of carry is batter, then I might listen, but until then, cocked and locked is the way.

A hammer slipping while decocking or when cocking it is a very likely posibility, especially when trying to cock it under stress. My wife, intending to carry her P238 in her purse while she researched & decided on a better method, didn't want to do so with it cocked & locked. She practiced diligently, with it unloaded, cocking & uncocking it.

Then the first time she tried to decock it with a round in the chamber, it slipped & she got a big bang! I lay it off to being nervous because it was the first time with live ammo. She followed the 'point in a safe direction' rule by going outside & pointing it at some dense woods behind the house, so no bad consequences except some embarassment & worry that the neighbors may have seen it.